Once one enters into the continuation of material existence, it is very difficult to get out. Therefore the Supreme Personality of Godhead comes Himself or sends His bona fide representative, and He leaves behind scriptures like Bhagavad-gita and Srimad-Bhagavatam, so that the living entities hovering in the darkness of nescience may take advantage of the instructions, the saintly persons and the spiritual masters and thus be freed. Unless the living entity receives the mercy of the saintly persons, the spiritual master or Krsna, it is not possible for him to get out of the darkness of material existence; by his own endeavor it is not possible.